Proportion and graphs (Edexcel GCSE Maths): Flashcards

$∝$ (e.g., $y ∝ x$)

$y = kx$ where $k$ is constant

Straight line through origin $(0,0)$

Also doubles

Constant gradient

$y ∝ \frac{1}{x}$

$y = \frac{k}{x}$ where $k$ is constant

Curved line (hyperbola/reciprocal shape)

Halves

Never touches or crosses axes

Numerator, variable in denominator

Symmetrical about line $y = x$

Inverse proportion